Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Physics

A charged particle is moving in a cyclotron, what effect on the radius of path of this charged particle will occur when the frequency of the ratio frequency field is doubled?

Which of the following is not correct about cyclotron?

For wiring in the home, one uses Cu wires or Al wires. What considerations are involved in this?

In a cyclotron, a charged particle ______.

Verify that the cyclotron frequency ω = eB/m has the correct dimensions of [T]^–1.

Describe the motion of a charged particle in a cyclotron if the frequency of the radio frequency (rf) field were doubled.

A ray of light incident at an angle θ on a refracting face of a prism emerges from the other face normally. If the angle of the prism is 5° and the prism is made of a material of refractive index 1.5, the angle of incidence is ______.

The phenomena involved in the reflection of radiowaves by ionosphere is similar to ______.

A rectangular block of glass ABCD has a refractive index 1.6. A pin is placed midway on the face AB (Figure). When observed from the face AD, the pin shall ______.

1. appear to be near A.
2. appear to be near D.
3. appear to be at the centre of AD.
4. not be seen at all.

A jar of height h is filled with a transparent liquid of refractive index µ (Figure). At the centre of the jar on the bottom surface is a dot. Find the minimum diameter of a disc, such that when placed on the top surface symmetrically about the centre, the dot is invisible.

A ray of light passes through a prism of refractive index `sqrt2` as shown in the figure. Find:

1. The angle of incidence (∠r₂) at face AC.
2. The angle of minimum deviation for this prism.

• Assertion (A): Propagation of light through an optical fibre is due to total internal reflection taking place at the core-cladding interface.
• Reason (R): Refractive index of the material of the cladding of the optical fibre is greater than that of the core.

Calculate the distance of an object of height h from a concave mirror of radius of curvature 20 cm, so as to obtain a real image of magnification 2. Find the location of the image also.

Give two reasons to explain why a reflecting telescope is preferred over a refracting telescope.

Use the mirror equation to show that an object placed between f and 2f of a concave mirror produces a real image beyond 2f.

Explain why the maxima at `theta=(n+1/2)lambda/a` become weaker and weaker with increasing n

For a single slit of width "a", the first minimum of the interference pattern of a monochromatic light of wavelength λ occurs at an angle of λa. At the same angle of λa, we get a maximum for two narrow slits separated by a distance "a". Explain.

Describe briefly how a diffraction pattern is obtained on a screen due to a single narrow slit illuminated by a monochromatic source of light. Hence obtain the conditions for the angular width of secondary maxima and secondary minima.

Two wavelengths of sodium light of 590 nm and 596 nm are used in turn to study the diffraction taking place at a single slit of aperture 2 × 10⁻⁶ m. The distance between the slit and the screen is 1·5 m. Calculate the separation between the positions of first maxima of the diffraction pattern obtained in the two cases.